Class 12 Electrostatic Potential And Capacitance CBSE Questions & Answers

The electric field between the plates of a fully charged capacitor is E. If a material of dielectric constant k is introduced between the plates, the electric field at a point between the plates

The plates of a parallel plate capacitor are 10 cm apart and have area equal to 2m2. If the charge on each plate is \({\rm{8}}.{\rm{85}} \times {\rm{1}}{0^{ - {\rm{1}}0}}C\) , the electric field at a point

The force with which the plates of a parallel plate capacitor, having charge Q and area of each plate as A, attract each other is

The magnitude of the electric field in the annular region of a charged cylindrical capacitor

If the potential difference between the plates of a capacitor is increased by 0.1%, the energy stored in the capacitor increases by very nearly

Three capacitors connected in series have an effective capacitance of 2 \(\mu {\rm{F}}\). If one of the capacitors is removed, the effective capacitance becomes 3 \(\mu {\rm{F}}\). The capacitance of the capacitor that is removed is

The effective capacitance of two capacitors of capacitances \({{\rm{C}}_{\rm{1}}}\) and \({{\rm{C}}_{\rm{2}}}\) (with \({{\rm{C}}_{\rm{2}}}\)> \({{\rm{C}}_{\rm{1}}}\)) connected in parallel is \({{25} \over 6}\) times the effective capacitance when they are connected in series. The ratio C2/C1 is

A parallel plate capacitor of value 1.77 \(\mu {\rm{F}}\) is to be designed using a dielectric material (dielectric constant 200, breakdown strength of \({\rm{3}} \times {\rm{1}}{0^{ - {\rm{6}}}}{\rm{V}}{{\rm{m}}^{ - {\rm{1}}}}\). In order to make such a capacitor, which can withstand a potential difference of 20 V across the plates, the separation d between the plates and the area A of the plates should be {tex\rm{ }}{\varepsilon _{\rm{o}}} = {\rm{ 8}}.{\rm{85 x 1}}{/tex}

A parallel plate capacitor of capacitance C is connected to a battery and is charged to a potential difference V. Another capacitor of capacitance 2C is similarly charged to a potential difference 2V. The charging battery is then disconnected and the capacitors are connected in parallel to each other in such a way that the positive terminal of one is connected to the negative terminal of the other. The final energy of the configuration is

A parallel combination of 0.1 M\(\Omega \) resistor and a 10 \(\mu {\rm{F}}\) capacitor is connected across a 1.5 V source of negligible resistance. The time (in seconds) required for the capacitor to get charged up to 0.75 V is approximately

Consider the situation shown in the figure. The capacitor A has a charge q on it whereas B is uncharged. The charge appearing on the capacitor B a long time after the switch is closed is

Two identical capacitors, have the same capacitance C. One of them is charged to potential \({{\rm{V}}_{\rm{1}}}\) and the other to \({{\rm{V}}_{\rm{2}}}\). The negative ends of the capacitors are connected together. When the positive ends are also connected, the decrease in energy of the combined system is

If the charge on a capacitor is increased by 2 coulomb, the energy stored in it increases by 21%. The original charge on the capacitor (in coulomb) is

A parallel plate capacitor of capacity 100 \(\mu {\rm{F}}\) is charged by a battery of 50 volts. The battery remains connected and if the plates of the capacitor are brought closer so that the distance between them becomes half the original distance, the additional energy given by the battery to the capacitor in joules is:

64 water drops having equal charges combine to form one bigger drop. The capacitance of the bigger drop, as compared to that of smaller drop will be